"Heartbreaking," said local resident Michael Coyne. "It's tough to fathom how somebody could do that to an innocent animal and just leave it here in the parking lot like a bag of trash."

Investigators believe the dog was already dead or close to death when it was left in the parking lot.

But there were no obvious signs of trauma.

Testing is taking place to determine the cause of death.

She was found on Sunday, and the MSPCA along with local police and Animal Control are turning to the public for help.

"I think it's appalling," said Carol Monast of North Attleboro. "I think that they should be found and prosecuted as if they had done this to a child or a human being because animals are like a human being."

On weekends, the park is popular with joggers and dog walkers, but can be very quiet during the week, according to people who live in the neighborhood.

The dog was placed on bedding -- a sheet and a comforter -- and was covered with a lightweight gray plastic tarp.

The case is being handled as an active animal cruelty investigation.

"If they're found, let them be left in the park and see how they like it," said Monast. "I think it would be a good way for them to realize what that poor animal was going through at the time."

Investigators say they're trying to identify the dog's owner, but so far, they have no leads.